The invention relates to a regulating device, in particular a motor vehicle parking brake with a regulating unit comprising a power-operated drive.
During the operation of a parking brake, it is necessary to adjust the length of the brake cable, due to wear of the brake shoes for example or the settling behavior of the brake cable for example. This is to avoid essentially unnecessary cable travel when the brake cable is tightened so that said brake cable can be tightened in a quick and reliable fashion.
Mechanical adjustment devices are known from the prior art, which are mostly integrated into the force flow of the brake pull cable as a type of “mechanical series connection”. The fundamental concept behind these types of adjustment devices is based on two teeth interlocking with each other and transmitting the cable force. As soon as the teeth are no longer interlocking with each other, the force flow is interrupted. Generally one of the teeth is designed as a rack and the other tooth as a latch. In this way, the latch engages in a specific tooth on the rack depending on wear.
With power-actuated parking brakes, electromotive parking brakes with a spindle drive for example, the adjustment takes place by means of path measurement in conjunction with corresponding control of the drive. The disadvantage with this is that path measurement and control of the drive require relatively expensive and error-prone components.